Diagnostic instrument



y 1937- I c. H. o. WITTIG 2,080,844

DIAGNOSTIC INSTRUMENT Filed Aug. 21, 1934 I8 36 ii l6 1 38 a 33 in? la G 3 i-" IO 37 g gi as l FIG. 3 '12 i I FIG.2 39

CARL H.O. WITTIG INVENTOR ATTORNEY Patented May 18, 1937 UNITED STATES PATENT OFFICE DIAGNOSTIC INSTRUMENT Application August 21, 1934, Serial No. 740,807

6 Claims.

The present invention relates to diagnostic instruments and has particular reference to a lamp mounting for use therewith.

It has been found in the case of certain diagnostic instruments such as ophthalmoscopes, that better results are obtained when the lamp filament bears a fixedand definite positional relation to the instrument head. One of the objects of the present invention is to provide a simple and rugged rotatable support for the lamp so that the filament may be properly aligned with the head. Other objects and advantages reside in certain novel features of construction, arrangement and combination of parts as will hereinafter be more fully disclosed and the novel features thereof will be pointed out in the appended claims.

In the drawing:

Fig. 1 is a front elevation of an ophthalmoscope. I

Fig. 2 is an enlarged vertical section of the upper portion of the ophthalmoscope with parts in elevation.

Fig. 3 is an enlarged view of the lamp mounting shown in Fig. 2.

Fig. 4 is a section taken on line 4-4 of Fig. 3.

Fig. 5 is a side elevation of the lamp socket, and

Fig. 6 is a detail view of a spring ring.

One embodiment of my invention is illustrated in the drawing wherein Fig. 1 shows an ophthalmoscope having the usual handle I0 and control button ll. Mounted in the handle I0 is a conducting tube I2 having a shoulder I3 for limiting its movement into the handle. The ophthalmoscope head I4 is carried by a sleeve I5 which telescopically engages the tube I2 and is provided with an enlarged annular portion I6 carrying a set screw I1 for engagement with a longitudinal slot I8 formed in the tube I2 so that the sleeve l5 may be moved longitudinally on the tube I2 while being held against rotation during such movement by the set screw H and slot I8. The usual ophthalmoscope prism I9 is carried at the upper end of the sleeve I5.

The upper end of the tube I2 is formed with an internal annular groove 20 for holding a spring ring 2I. A lamp socket 22 for holding a lamp 23 is provided with an external annular groove 24 and is adapted to be driven into the upper end of the tube I2 until the two annular grooves are in alignment and then the spring ring ZI will hold the socket against longitudinal. displacement with. respect to the tube. An enlarged shoulder 25 on the socket 22 serves to limit the movement into the tube and has. a knurled edge 26 so that it may be gripped for turning the socket 22 and lamp 23 with respect to the tube for aligning the lamp filament. In order that the lamp filament will remain in its adjusted position it is essential that the socket 22 turn with a great deal. of friction and to increase this friction slots'2l are formed in the lower portion of the socket so that such lower portion may bear resiliently against the interior of the tube I2.

The lamp 23 is formed with a long cylindrical base 28 on which is slidably mounted a sleeve 29 carrying a lens 30 while a second sleeve 3| carrying a diaphragm 32' is slidably mounted on the lens carrying sleeve 29.

A contact 33, spaced from the tube I2 by means of insulation 34, is pressed against the center contact 35 of the lamp base 23 by means of a spring 36 connected to a conductor 31 which is spaced from the tube I2 by means of insulation 38 into which said conductor is threaded. The conductor 31 is shaped at its lower end in the form of a push plug 39 which engages a complementary electrical contact, not shown, in the base III. In use, current may be supplied to the lamp through the conducting tube I2 and the conductor 31, either from batteries located in the handle III or from an outside source.

The best results are obtained from an ophthalmoscope when the lamp filament is perpendicular to the plane of the ophthalmoscope head. To so adjust the lamp filament, the set screw ll is withdrawn from the slot I8 and the head I4 and sleeve I9 are removed from the tube I2. The knurled shoulder 26 is then turned until the filament of the lamp 23 lies in the same plane as the slot l8. Only one adjustment is usually necessary for a particular lamp bulb .as the frictional resistance to the turning of the socket is sufficient to retain the lamp in its adjusted position. The annular grooves 20 and 24 and the spring ring 2| serve to hold the socket against longitudinal movement relative to the tube.

Although I have illustrated and described my invention in connection with an ophthalmoscope, it can be as well applied to many other similar diagnostic instruments, such as retinoscopes, otoscopes or the like. It is readily apparent that my improved lamp mounting is easy and inexpensive to manufacture and yet rugged and efiective in operation. From the foregoing it is also apparent that I obtain. the objects of my invention and provide an improved mounting for the lamp of a diagnostic instrument so that the filament of the lamp may be readily aligned with the instrument.

Various modifications can obviously be made without departing from the spirit of my invention.

I claim:

1. In a diagnostic instrument of the type described, an illuminating device comprising a tube, a lamp socket and means for rotatably fastening said socket in said tube, said means comprising an annular groove on said socket, an internal annular groove in said tube and a spring ring mounted in said grooves for holding said socket and said tube in assembled relation with said grooves in alignment.

2. In a diagnostic instrument of the type described, an illuminating device comprising a tube, a lamp socket, means for rotatably fastening said socket in said tube, said means comprising an annular groove on said socket, an internal annular groove in said tube, and a spring ring mounted in said grooves for holding said socket and said tube in assembled relation with said grooves in alignment, and means for increasing the frictional relation of said socket and said tube.

3. In a diagnostic instrument of the type described, an illuminating device comprising a tube, a lamp socket, means for rotatably fastening said socket in said tube, said means comprising an annular groove on said socket, an internal annular groove in said tube, and a spring ring mounted in said grooves for holding said socket and said tube in assembled relation with said grooves in alignment, and means for increasing the frictional relation of said socket and said tube, said last-named means comprising a split portion. on said socket bearing against the inner wall of said tube.

4. In a diagnostic instrument of the type described, a tube, an instrument head having a longitudinal bore for receiving said tube, cooperating means between said tube and one end of said bore for permitting longitudinal relative movement while preventing rotative relative movement, an incandescent filament lamp, a socket for said lamp, means for rotatably mounting said socket in said tube comprising an annular groove on said socket, an internal annular groove in said tube and means for holding said socket and said tubes in assembled relation with said grooves in alignment, and means for increasing the frictional relation of said socket to said tube.

5. In a device of the character described, an ophthalmoscope head, a sleeve secured to the rear side of said head, a prism secured in one end of said sleeve, the other end of said sleeve being open, an illuminating device adapted to fit in the open end of said sleeve, said illuminating device comprising a tube, a lamp socket and means for rotatably fastening said socket in said tube, said means comprising an annular groove on the socket, an internal annular groove in said tube and means extending into both grooves for holding said socket and said tube in assembled relation with said grooves in substantial alignment.

6. In a device of the character described, an illuminating device comprising a tube, a lamp socket and means for rotatably fastening said socket in said tube, said means comprising an annular groove on said socket, an internal annular groove in said tube, and a spring ring mounted in said grooves for holding said socket and said tube in assembled relation with said grooves in alignment, said tube having a longitudinal groove in its outer wall, an instrument head, a sleeve secured to said instrument head for receiving said tube and said socket and a projection extending into said sleeve in predetermined relation to said instrument head for engaging the last-named groove and preventing relative rotation between said sleeve and said tube.

CARL H. O. WI'I'I'IG. 

